Unitary case for an angular drive

ABSTRACT

The application relates to a unitary case for a plurality of angular drives which comprises at least one bevel gear step with a first bevel gear and a second bevel gear, and which is provided for achieving various angles between a transmission input shaft and a transmission output shaft. The second bevel gear is coupled to the transmission output shaft in an indirect rotationally fixed manner. The unitary case is designed for a plurality of possible angular outputs wherein multiplication is substantially constant and the outer diameters of the individual bevel gears are substantially identical.

The invention relates to a unitary case for an angular drive of atransmission unit having the individual features of the characterizingportion of claim 1. It also relates to a case for a transmission unitand a transmission unit.

Transmission units are available in many different configurations. Theydiffer, for example, with regard to how the speed/torque conversion isrealized, which can be purely mechanical or combined with otherconverting options, for example. Especially for the transmission unitswith purely mechanical power transmission or with a mechanical combinedwith another power transmission the requirement for a universallyapplicable transmission unit is increasing. In order to realize theoutput drive at a certain angle relative to the transmission inputshaft, angular drives are used for such transmission units which arecombined with a base transmission unit. With these, a certain angle canbe realized between the transmission input shaft and the transmissionoutput shaft. For varying requirements, i.e. varying output angles,varying drive torque transmission and tilting angles relative to theroad, a separate, specially configured transmission case or a certainunitary case has to be provided which encompasses the angular driveaccordingly. Due to the many different case variants that are possibleand the low degree of standardization production is more complex andcosts are high.

Therefore, the aim of the invention is to further develop a case for aplurality of angular drives for use in transmission units withmechanical or combined power transmission such that the overalltransmission unit can be equipped with a standardized case for varyingoutput drive variants and that the overall transmission unit will have aminimal overall length.

It should also be possible to develop the overall transmission unit forvarious application requirements by means of an easy modification of abase transmission unit. In particular, the possibility of creating aunitary case for realizing the most varied angular drives should beprovided. The solution of the invention should also be characterized byminor constructive efforts.

The solution of the invention is characterized by the features of claims1, 10 and 13. Advantageous embodiments are reflected in the sub-claims.

In accordance with the invention, a unitary case for a plurality ofangular drives comprising at least one bevel gear step with a firstbevel gear and a second bevel gear for realizing various angles betweena transmission input shaft and a transmission output shaft, where thesecond bevel gear can be coupled to the transmission output shaft in anat least indirect rotation-proof manner, for a plurality of thetheoretically possible angular outputs has a virtually constantmultiplication i and a constant outside diameter of the individual bevelgears with identical outside dimensions. In the unitary case, bearingreceiving devices are assigned to the transmission output shaft and/orthe second bevel gear. Said devices are formed by the inside contour ofthe unitary case and/or by replaceable bearing support elements that aredimensioned for receiving the bearings of the transmission output shaft.

Most of the theoretically possible angular drives that can be placed inthe unitary case can be defined by two limit positions of theintersecting points of the flank lines of the bevel gears. A first limitposition for the angular drive with the largest theoretically possibleor desired angle between the transmission input shaft and thetransmission output shaft is characterized by the intersection locatedclosest to the case and a second limit position for the angular drivewith the smallest theoretically possible angle between the transmissioninput shaft and the transmission output shaft is characterized by theintersection of the flank lines located furthest away from the case. Thelimit positions preferably define a range between 90 and <180° for theangular drive.

Therefore, the individual angular drives differ merely with regard tothe angle between the transmission input shaft and the transmissionoutput shaft in installed condition, which also corresponds to the anglebetween the bisecting lines of the individual bevel gears and thus theentrance and exit of the angular drive. The solution of the inventionallows that various angular outputs are encompassed by one single case.The output angle is determined only by the production method, especiallyby how the inside contour is formed by means of milling, cutting or thelike, and by the configuration of the bearing receiving devices.Therefore, with regard to the dimensions of the transmission unit thecustomer does not depend on various angular outputs. Instead, a unitarycase can be offered for a transmission unit consisting of a basetransmission unit with various angular outputs.

The inside contour for any theoretically possible angle between thetransmission input shaft and the transmission output shaft can beprovided by means of metal cutting the inside wall of the caseaccordingly. When a corresponding bearing receiving device is used, itpreferably has two bearing support elements that are assigned to thetransmission output shaft, each for receiving at least one bearing, afirst bearing support element and a second bearing support element.

The bearing support elements each form a running surface for theindividual bearings. The first bearing support element serves to supportthe end area of the transmission output shaft in the case, while thesecond bearing support element serves to support the transmission outputshaft in the area of the exit of the case.

According to an especially advantageous embodiment with a minimum numberof components, at least one of the bearing support elements, the firstand/or second bearing support element, forms a part of the outside wallof the case. Preferably, both bearing support elements are components ofthe case.

According to a further development, the second bearing support elementis already provided with connections and/or lead-throughs for fuel linesand/or ducts for electric lines so that these can be additionallymodified for a certain angular drive separate from the rest of the case.

Further standardization is achieved by disposing a second heat exchangeron the second support element.

The bearing support elements can be mounted on the inside wall of thecase in various different ways, for example by means of mountingelements. The bearing support elements preferably have uniform outsidedimensions, especially in the surface areas contacting the inside wallof the case or interacting with indentations or projections on theinside wall of the case. This offers the advantage that the unitary casewithout the bearing support elements is also configured uniformly forall theoretically possible angular drives, and only the actual supportsurfaces for the bearings on the bearing support elements will vary.

The case for a transmission unit comprising a base transmission unit andan angular drive with a base transmission case that is assigned to thebase transmission unit is equipped with a unitary case that is assignedto the angular drive as defined in any of the claims 1 to 10.

If, according to a special embodiment of the base transmission unit, aplurality of channels for supplying fuel and/or lubricant and/or coolantis disposed in the base transmission case, respective complementaryconnecting channels in the unitary case are assigned to the channels forsupplying fuel and/or lubricant and/or coolant forming channels thatextend through the transmission unit for supplying fuel and/or lubricantand/or coolant when the base transmission case and the unitary case arejoined.

The transmission unit can be a mechanical transmission unit, which meansthat the speed/torque conversion is achieved solely by means ofmechanical transmission elements. It is conceivable, however, that thetransmission unit has a combined power transmission. The followingembodiments are conceivable, for example:

-   -   a) mechanical-hydrodynamic combination transmission    -   b) mechanical-hydrostatic combination transmission    -   c) mechanical-electric combination transmission comprising a        base transmission disposed between the transmission input shaft        and the transmission output shaft and an angular drive that is        connected with the output drive of the base transmission in an        at least indirect rotation-proof manner.

The angular drive comprises at least one bevel gear step with a firstbevel gear and a second bevel gear, where the second bevel gear can becoupled with the transmission output shaft in an at least indirectrotation-proof manner.

The first bevel gear can be connected with the mechanical transmissionpart in various ways. The following are conceivable methods:

-   -   a) coupling with an output drive shaft of the mechanical        transmission part    -   b) coupling with a transmission element of the mechanical        transmission part.

The rotation-proof connection can be non-positive and/or positivelocking. An embodiment is preferably used where the mechanicaltransmission part comprises a planetary gear step and where therotation-proof connection of the first bevel gear is realized with theinternal gear acting as a transmission element. Again, the connectioncan be non-positive and/or positive and/or material-locking. Preferably,however, the first bevel gear and the transmission element of theplanetary gear step are configured as an integral unit.

The first bevel gear of the angular drive and a transmission element ofthe base transmission unit forming the output drive of the basetransmission unit are preferably connected in a direct rotation-proofmanner and disposed spatially close together.

If the base transmission unit comprises at least one planetary gear setwith at least one internal gear, a sun wheel, planetary wheels and abridge or a spur gear set the output drive of the base transmission unitis formed by an element of the planetary gear set or the spur gear set.According to an especially preferred embodiment, the first bevel gear ofthe bevel gear step can be coupled with the internal gear of theplanetary gear step so as to be rotation-proof.

If the first bevel gear is coupled with an internal gear of themechanical transmission part in a rotation-proof manner, and if the casehas the above described form the first bevel gear can have an especiallylarge diameter, which results in an especially short and compact overallsize. The second bevel gear coupled with the output drive shaft ispreferably installed and removed via the flanging of the overall angulardrive. The angular drive elements are positioned separately from thestandardized positioning of the output drive, i.e. the transmissionoutput shaft, which is why the bearings do not have to be readjustedwhen the angular drive is flange-mounted. The cooling devices that areotherwise flange-mounted to the cover of a base transmission with noangular drive can be mounted in the end area of the angular drive. Thenecessary connecting lines will then not have to be produced withflexible hoses. They can enter the case in the form of channels.

The individual elements of the bevel gear step can be configured with astraight tooth system or a helical tooth system. Preferably, toothsystems are used where the individual tooth element has a constant toothheight. For the configuration with a helical tooth system an involutetooth system is preferably used. The helical tooth system allows anespecially quiet operation.

The solution of the invention allows that all angles and output drivetorques are covered by one single angular drive case. Due to thediameter-emphasized construction the angular drive is highly compact andshort. Maintenance and the assembly and disassembly of the bearingwheels and gears are very easy.

The solution of the invention will be explained below by means of thefigures, showing the following:

FIG. 1 is a schematically simplified illustration of a view in axialdirection of a transmission unit configured in accordance with theinvention;

FIG. 2 is a schematically simplified illustration of the positioning ofthe transmission output shaft A at two different angles between thetransmission input shaft and the transmission output shaft;

FIG. 3 is a simplified illustration according to a view A of FIGS. 1 and2 showing the possibility of mounting the angular drive;

FIGS. 4.1 to 4.4 illustrate the possibilities of using the transmissionunit of the invention for the drive mechanism of a bus with varyingrequirements;

FIG. 5 illustrates a further development of the unitary case.

FIG. 1 is a schematically simplified illustration of a section of anaxial profile of a transmission unit 1 showing the installation inaccordance with the invention of an angular drive 4 in the basetransmission unit 25. The transmission unit has a transmission inputshaft E and at least one transmission output shaft A acting as outputdrive. The transmission input shaft E and the transmission output shaftA are disposed such that their theoretical axes of rotation R_(E) andR_(A) are at an angle relative to each other. The transmission unit 1comprises at least one base transmission unit 25 disposed between thetransmission input shaft E and the transmission output shaft A. The basetransmission unit 25 comprises a mechanical transmission part 2 and abevel gear step 3 configured as an angular drive 4, which is coupled tothe transmission output shaft A.

The transmission unit 1 also has a transmission case 5, which consistsof at least two parts. In this case, it comprises at least a basetransmission case 6 and a unitary case 7 which at least partiallyencompasses the angular drive 4 and which can be connected with thetransmission case 6. However, the unitary case 7 can also consist ofmultiple parts.

The angular drive 4, which is formed by a bevel gear step 3, has atleast two bevel gears working together, a first bevel gear 8 and asecond bevel gear 9. The first bevel gear 8 is disposed coaxiallyrelative to the transmission input shaft E. The second bevel gear 9,which can be coupled to the transmission output shaft A so as to berotation-proof, is disposed at a certain angle relative to the firstbevel gear 8.

The theoretical axes of rotation of the individual bevel gears or theiraxes of symmetry that correspond to the theoretical axes of rotation ofthe transmission input shaft and the transmission output shaft R_(E) andR_(A), intersect at a point 10 on the axis of symmetry of thetransmission unit 1. At said point, the flank lines F of the toothsystem of the individual bevel gears also intersect when projected on acommon level E with the axis of symmetry of the transmission S_(G). Theflank lines are referenced F₈₁, F₈₂ and F₉₁, F₉₂. The tooth systems ofthe individual bevel gears are preferably configured as a straight toothsystem, but a configuration as a helical tooth system or a curved toothsystem with curving flank lines is also conceivable. In bevel gears withcurved flank lines, these can be configured as circular arcs, involutesor epicycloids. In the illustrated case, the bevel gears 8 and 9 have aconstant tooth height Z_(H8) and Z_(H9). The following explanationsrelate to the straight tooth system specified in FIG. 1.

These explanations can be applied analogous to other tooth systems.

For a certain base transmission unit 25 angular drives 4 are providedfor realizing various angles between the transmission input shaft E andthe transmission output shaft A. Said angular drives 4 are configuredsuch that the individual flank lines of a straight tooth system or theflank lines projected on a level with the gear axis S_(G) can formvarious angles with the gear axis S_(G). The individual angular drives 4that are theoretically suitable for a unitary case 7 for realizingvarious angles between the transmission input shaft E and thetransmission output shaft A, which are characterized by a substantiallyconstant multiplication between the individual bevel gears 8 and 9 andby substantially constant outside diameters of the individual bevelgears 8 and 9, cover a certain area in axial direction of the gear axisS_(G) with regard to the intersecting points of their flank lines F₈₁,F₈₂, F₉₁, F₉₂ with the gear axis S_(g). The configuration of thetransmission case 5 and the unitary case 7 encompassing the angulardrive is based on said area. In order to preferably realize a standardcase 5, including the unitary case 7, for a base transmission unit 1under various output drive conditions, i.e. varying angles of thetransmission output shaft A relative to the transmission input shaft E,the second unitary case 7 is standardized in such a way that it issuitable for receiving all theoretically possible or desired angulardrives 4, where the only differentiating criterion is the angle betweenthe transmission input shaft E and the transmission output shaft A,while the multiplication ratio and the outside diameter of the bevelgears remain constant for the individual theoretically possible angles.Therefore, the base transmission case of the unitary case 7 isconfigured for the two theoretical limit cases so that the intersectingpoint 10 of the flank lines of the bevel gears 8 and 9 of the bevel gearstep 3 is closest to and furthest away from the transmission case 5 orthe unitary case 7 in axial direction.

The first limit case can correspond to the situation of an angular drive4 of 90°, for example, or even a higher than 90° angle. It does not haveto be determined precisely, but it should be within the theoreticallypossible range, and the structural feasibility should also be taken intoconsideration. However, an angular drive with an angle in the rangebetween 90° and <180° between the transmission input shaft E and thetransmission output shaft A is preferable. An angle of <180° representsthe second limit case. As mentioned above, the outside contour forvarious angular drives 4 with substantially identical multiplication iand an identical outside diameter d_(A) of the individual bevel gears 8and 9 remains constant, while the adaptation to various angular drives,especially the arrangement of the bearings is achieved by means ofconfiguring or cutting the inside contour of the case, especially theunitary case 7.

The embodiment of the unitary case according to the invention for aplurality of the theoretically possible angular output drives withvirtually constant multiplication i and identical outside diameter ofthe individual bevel gears 8 and 9 for various angular drives withidentical outside dimensions comprises bearing receiving devices 20 thatare assigned to the transmission output shaft A and/or to the secondbevel gear 9 in the unitary case 7. The bearing receiving devices 20 areformed by the inside contour 21 of the unitary case and/or byreplaceable bearing support elements that are dimensioned for receivingthe bearings of the transmission output shaft. The illustrated casecorresponds to the second alternative where the bearing support elements22 and 30 are assigned to the transmission output shaft. They are usedfor receiving at least one bearing 31 and 32 each. The bearing supportelements 22 and 30 each form a running surface 38 and 39 for theindividual bearings 31 and 32. The first bearing support element 22 isused for supporting the end area of the transmission output shaft A inthe case 7.

The second bearing support element 30 is used for supporting thetransmission output shaft A in the area of the exit from the case 7.Both bearing support elements 22, 30, the first and/or second bearingsupport element, form a part of the outside wall 40 of the case 7. Thesupport elements 22 and 30 can be mounted on the outside wall 43 of thecase by means of mounting elements 41 a, 41 b, 42 a, 42 b.

The tight coupling between the first bevel gear 8 and the elements ofthe mechanical transmission part 2 can be achieved by various differentmethods. In the illustrated preferred embodiment a mounting method wasselected, which is characterized by an especially compact size for theoverall transmission unit 1, because the first bevel gear 8 can beconfigured with a very large bevel gear diameter. In this case, it ismounted to a transmission element of a planetary gear set 27 of the basetransmission unit 25, which at the same time forms the output drive 15for the base transmission unit 25, and thus the entrance for the angulardrive 4. The planetary gear set comprises a sun wheel 12, an internalgear 26, planetary wheels 13 and a bridge 14. The transmission elementforming the output drive 15 is formed by the internal gear 26 of theplanetary gear set 27. The coupling is achieved by a rotation-proofconnection by means of positive and non-positive locking. Therotation-proof connection is referenced 33. It is realized by theengagement of complementary driver elements 18 and 19 on the internalgear 26 and the first bevel gear 8. The bevel gear 8 is configured witha respective outside tooth system 28 which can engage in a complementaryinside tooth system 29 on the internal gear 26. The inside tooth system29, which is provided on the internal gear 26 in any case, is preferablyused for this. To this aim, the internal gear is lengthened only inaxial direction as seen in installed position in the transmission unit1, so that in addition to the planetary wheels 34 of the planetary gearset 27 the internal gear interacts with the outside tooth system 28 ofthe bevel gear 8.

To this aim, the bevel gear 8 has a respectively configured outsidetooth system 28 in a second partial section 35 which is free of thebevel tooth system.

Furthermore, the case 7 encompassing the angular drive 4 and which ininstalled position forms a modular unit in combination with the basecase 6, is assigned to the angular drive 4. In order to realize a unitwhich can be preassembled the angular drive 4 is provided withrespective bearing devices 36 and an axle 37 for supporting, which isdisposed stationary in the case 7. The case 7 can consist of one part,but it can also consist of multiple parts, as shown in FIG. 1. Themultiple part configuration is preferred so as to facilitate theassembly.

The advantage of the angular drive 4 embodiment as a modular unit isthat it can be integrated easily as one unit into the overalltransmission unit 1. This is accomplished by pushing together, and thusengaging the outside tooth system 28 and the inside tooth system 29 ofthe internal gear. It is secured against shifting in axial direction byconnecting the first bevel gear 8 with the case 7 and by connecting thecase 7 and the base transmission case 6 of the base transmission unit25, which is required for realizing the overall transmission unit 1.Additional securing elements are not required.

FIG. 2 is a schematically simplified representation of the positioningof the transmission output shaft A at two different angles between thetransmission input shaft E and the transmission output shaft A. Variant1 corresponds to an angle α₁ of 60° between the transmission input shaftE and the transmission output shaft A, while Variant II refers to thepositioning with an arrangement of the transmission output shaft Arelative to the transmission input shaft E at an angle α₂ of 80°.

The unitary case 7 also has a through-opening 23 for the exit of thetransmission output shaft A. Preferably, a constant theoretical openingrange 23 is provided for all unitary cases 7. The max. size correspondsto the angular range a which can theoretically be covered by thetransmission output shaft A.

The unitary case 7 can be connected non-positive and/or positive lockingwith the transmission case 6. They are preferably coupled via screwand/or plug-in connections. The indentations and through-openings on thebase transmission case 6 and on the unitary case 7 required forrealizing the connection are preferably configured such that they can beturned in circumferential direction of the transmission unit 1 so as torealize various arrangements for the bevel gear step 3, especially thesecond bevel gear 9 and thus the angular drive 4 relative to theinstalled position of the transmission unit, and thus of thetransmission case 5 relative to the latter. Possible exemplary positionsare shown in FIGS. 3 a and 3 b for a view referenced A according to FIG.1 or 2. This possibility is of enormous importance, especially when thetransmission case 5 has a certain design that is tied to a certaininstallation position. This is always the case when grooves or channelsare provided, for example, for lubricants or the like. The possibleinstallation positions for output drives shown in FIG. 3 are designatedwith A′ and A″, where A′ represents an embodiment suitable for left-handtraffic and A″ in FIG. 3 b represents an embodiment for right-handtraffic.

The embodiment of the unitary case 7 described in FIGS. 1 and 2 alsoallows a method of disassembling the second bevel gear 9 which departsfrom the conventional method.

While the second bevel gear 9 in the conventional designs was removed inthe direction of the axis of symmetry of the transmission output shaft Athe embodiment of the unitary case 7 of the invention allows that theunitary case 7 is first released from the rest of the transmission case5 and when the transmission output shaft A has been released from thebevel gear 9, the latter is laterally rolled out of the interior space11 formed by the unitary case 7. This makes it possible to shift theentire bevel gear step 3 further into the interior of the transmissioncase 5 in axial direction, because the unitary case 7 no longer dependson the area of the through-opening 23 in the transmission output shaft Ahaving a size that allows the second bevel gear 9 to be removed in thesame direction.

Other possibilities for realizing the removal of the second bevel gear 9require a respective configuration of the opening 23. According to analternative embodiment, which is not shown, the through-opening of thetransmission output shaft A can be elliptic. In this case, the max.dimension corresponds to the outside diameter d_(A) of the second bevelgear 9. For removal, the connection between the transmission outputshaft A and the second bevel gear 9 is likewise released first and thesecond bevel gear 9 is moved to the elliptic opening by means oftilting.

The configuration of the transmission case 5 according to FIGS. 1 to 3,especially the unitary case 7, allows that a unitary case is created bymeans of which various angular drives 4 can be covered. The output driveangle is defined only by the configuration or production and shaping ofthe inside contour in the area of the second bevel gear, which iscoupled to the transmission output shaft A. By separating the case intoa base transmission case 6 and a so-called unitary case 7 the angulardrive 4 can be shifted further in the direction of the transmissioninput shaft in axial direction compared to conventional configurations.

Therefore, the very short overall size is achieved via theflange-mounting of the overall angular drive. The above describedpreferred disassembly method allows a free configuration of the outputdrive side and results in a very short size, which also saves material.The base transmission unit can be tested without an angular drive 4.

FIG. 4 shows examples of possible applications of a transmission unit 1of the invention with a unitary case comprising the base transmissioncase 6 and the unitary case 7. The term unitary case 7 should not beunderstood to mean that it allows a complete closure. It can also beprovided with openings, which can be covered by lid-shaped elements.

FIG. 4.1 illustrates the transmission unit 1 of the invention used in abus drive system with a transversely installed drive mechanism 30 fordriving an axle 31 disposed between the second and third door of a bus.The drive mechanism 30 is coupled to the transmission unit 1 fortorque/speed conversion. The output drive shaft 32 of the mechanicaltransmission part runs coaxial relative to the transmission input shaftE. The axle drive is achieved via the angular drive 4.51 centrically onthe axle 31. The angular drive 4.51 has a 60 or 65° angle. Thisembodiment is suitable especially for right-hand traffic.

FIG. 4.2 illustrates an embodiment according to FIG. 4.1 by means of aschematically simplified view of a bus drive system. Again, the drivemechanism 30 is installed transversely, again with a centric axle drive.The embodiment differs from the one described in FIG. 4.1 by a change inthe direction of the power flow between the drive mechanism 30 and thetransmission unit 1. This embodiment is especially suitable forleft-hand traffic.

FIGS. 4.3 and 4.4 illustrate exemplary applications in so-called lowplatform busses where the drive mechanism 30 again is disposedtransversely to the driving direction and the portal axis 31 is drivenoff-center, i.e. offset, via an angular drive 4.53 or 4.54. Theembodiment in FIG. 5.3 is suitable for right-hand traffic, and theembodiment in FIG. 5.4 is suitable for left-hand traffic. The angulardrive, i.e. the angle between the transmission input shaft E and thetransmission output shaft A is 80° in this case.

FIG. 5 illustrates a preferred further development of the unitary caseas per FIGS. 1 to 4 where the heat exchanger 43 is flange-mounteddirectly to the transmission case in the area of the transmission outputshaft A. The oil tubes used in conventional designs should beeliminated, which is achieved by respectively configuring the unitarycase 7 with respectively integrated cooling channels 44, preferablyprovided directly in the housing wall.

Reference List

-   E transmission input shaft-   A transmission output shaft-   1 transmission unit-   2 mechanical transmission part-   3 bevel gear step-   4 angular drive-   5 transmission case-   6 base transmission case-   7 unitary case-   8 first bevel gear-   9 second bevel gear-   10 intersecting point between the axes of symmetry-   11 interior space-   12 sun wheel-   13 planetary wheels-   14 bridge-   15 output drive of the base transmission-   16 outside circumference of the first bevel gear-   17 inside circumference internal gear-   18 driver elements-   19 driver elements-   20 bearing receiving arrangements-   21 inside contour-   22 bearing support element-   23 through-opening-   25 base transmission unit-   26 internal gear-   27 planetary gear set-   28 outside tooth system-   29 inside tooth system-   30 bearing support element-   31 bearing-   32 bearing-   33 rotation-proof connection-   34 planetary wheels-   35 second partial section of the bevel gear-   36 bearing arrangement-   37 axle-   38 running surface-   39 running surface-   40 outside wall-   41,42 mounting elements-   43 heat exchanger-   F₈₁, F₈₂ and F₉₁, F₉₂—flank lines of the tooth systems of the bevel    gears

1. Unitary case for a plurality of angular drives, comprising at leastone bevel gear step with a first bevel gear and a second bevel gear soas to realize various angles between a transmission input shaft and atransmission output shaft, where the second bevel gear can be coupledwith the transmission output shaft in an at least indirectlyrotation-proof manner, characterized by the following features: 1.1 theunitary case is configured for a plurality of the theoretically possibleangular drives with the following features: multiplication i isvirtually constant and the outside diameter of the individual bevel gearis virtually identical with identical outside dimensions; 1.2 in theunitary case, bearing receiving devices are assigned to the transmissionoutput shaft and/or the second bevel gear; 1.3 the bearing receivingdevices are formed by the inside contour of the unitary case and/or byreplaceable bearing support elements that are dimensioned for receivingthe bearings of the transmission output shaft.
 2. Unitary case asdefined in claim 1, characterized by the following features: 2.1 theplurality of the theoretically possible angular drives that can beplaced in the unitary case can be defined by two limit positions of theintersecting points of the flank lines of the bevel gears; 2.2 a firstlimit position for the angular drive with the largest theoreticallypossible angle between the transmission input shaft and the transmissionoutput shaft is characterized by the intersection located closest to thecase and a second limit position for the angular drive with the smallesttheoretically possible angle between the transmission input shaft andthe transmission output shaft is characterized by the intersection ofthe flank lines located furthest from the case.
 3. Unitary case asdefined in claim 2, characterized in that the limit positions define arange of the angular drive between 90 and <180°.
 4. Unitary case asdefined in any of the claims 1 to 3, characterized in that the insidecontour can be generated for any theoretically possible angle betweenthe transmission input shaft and the transmission output shaft byrespectively metal cutting the inside wall of the case.
 5. Unitary caseas defined in any of the claims 1 to 3, characterized by the followingfeatures: 5.1 the bearing receiving device of the transmission outputshaft has two bearing support elements assigned to the transmissionoutput shaft for receiving at least one bearing each, a first bearingsupport element and a second bearing support element; 5.2 the bearingsupport elements each form a running surface for the individualbearings.
 6. Unitary case as defined in claim 5, characterized by thefollowing features: 6.1 a first bearing support element serves tosupport the end area of the transmission output shaft in the case; 6.2 asecond bearing support element serves to support the transmission outputshaft in the area of the exit from the case.
 7. Unitary case as definedin any of the claims 5 or 6, characterized in that at least one of thebearing support elements, the first and/or second bearing supportelement, forms a part of the outside wall of the case.
 8. Unitary caseas defined in any of the claims 6 or 7, characterized in that the secondbearing support element is provided with connections and/orlead-throughs for fuel lines and/or ducts for electric lines.
 9. Unitarycase as defined in any of the claims 6 to 8, characterized in that aheat exchanger is disposed on the second support element.
 10. Unitarycase as defined in any of the claims 5 to 9, characterized in that thesupport elements can be mounted on the inside wall of the case by meansof mounting elements.
 11. Case for a transmission unit comprising a basetransmission unit and an angular drive with a base transmission caseassigned to the base transmission unit and a unitary case assigned tothe angular drive, as defined in any of the claims 1 to
 10. 12. Case asdefined in claim 11, characterized by the following features: 12.1 inthe base transmission case a plurality of channels is disposed forsupplying fuel and/or lubricant and/or coolant; 12.2 respectivecomplementary connecting channels in the unitary case are assigned tothe plurality of channels for supplying fuel and/or lubricant and/orcoolant forming channels for supplying fuel and/or lubricant and/orcoolant that extend through the transmission unit when the basetransmission case and the unitary case are joined.
 13. Transmission unit13.1 with a transmission input shaft and a transmission output shaft;13.2 with a base transmission disposed between the transmission inputshaft and the transmission output shaft and an angular drive, which isconnected with the output drive of the base transmission in an at leastindirectly rotation-proof manner; 13.3 the angular drive comprises atleast one bevel gear step with a first bevel gear and a second bevelgear, where the second bevel gear can be coupled to the transmissionoutput shaft in an at least indirectly rotation-proof manner; 13.4 witha case as defined in any of the claims 10 to
 12. 14. Transmission unitas defined in claim 13, characterized in that the first bevel gear ofthe angular drive and a transmission element of the base transmissionunit forming the output drive of the base transmission unit can beconnected so as to be directly rotation-proof and that they are disposedspatially close together.
 15. Transmission unit as defined in claim 14,characterized by the following features: 15.1 the base transmission unitcomprises at least one planetary gear set with at least one internalgear, a sun wheel, planetary wheels and a bridge or a spur gear set.15.2 the output drive of the base transmission unit is formed by anelement of the planetary gear set or the spur gear set.
 16. Transmissionunit as defined in claim 15, characterized in that the first bevel gearof the bevel gear step can be coupled to the internal gear of theplanetary gear step so as to be rotation-proof.
 17. Transmission unit asdefined in any of the claims 15 or 16, characterized in that thecoupling is non-positive and/or positive locking.
 18. Transmission unitas defined in any of the claims 15 or 16, characterized in that therotation-proof coupling is realized by means of an integral constructionof the first bevel gear and the output drive shaft of the mechanicaltransmission part or the first bevel gear and the transmission elementof the mechanical transmission part.
 19. Transmission unit as defined inany of the claims 13 to 18, characterized in that the tooth system ofthe interacting bevel gears is configured as a straight tooth system.20. Transmission unit as defined in any of the claims 13 to 18,characterized in that the tooth system of the interacting bevel gears ofthe bevel gear step is configured as a helical tooth system. 21.Transmission unit as defined in any of the claims 19 or 20,characterized in that the bevel gears of the bevel gear step havetoothed elements with a constant tooth height.